Cam lapping machine



y 1942- H. S. INDGE ETAL 2,290,755

CAM LAPPING MACHINE 1 Filed A ril 1, 1941 s Sheets-Sheet 2 HEHEERTE/VUEE .JaH/v 5 55w 5/? Mums MM,

July 21, 1942. H. s. INDGE ETAL CAM LAPPING MACHINE Filed April 1, 1941 6 Sheets-Sheet 3 JOHN CEHKER' M -EJIQ;

July 21, 1942 s, [NDGE ETAL 2,290,755

CAM LAPPING MACHINE,

Filed April 1, 1941 6 Sheets-Sheet 4 gwuowtoo HEREEH 7"5f/VDEE 3% JoH/v CIEH KER Mum M y 1942- H. s. INDGE EI'AL 2,290,755

CAM LAPPING MACHINE v Filed April 1, 1941 e Sheets-sheet e 235 F- 7 X 234 233 224 I awe/M10 1. HEREEE' T5 [N0 55 JOHN CEHKEH Gum/nut Patented July 21, 1942 CAM LAP-PING MACHINE Herbert .S. Indge, Westboro, and John C. Baker, Worcester, Mass, assignor to Norton Company, Worcester, Mass, a corporation of Massachusetts Application Aprill, 1941, Serial No. 386,356

(.Cl. l151) 12 Claims.

Theinvention relates to lapping machinesxand more particularly to acam lapping machine.

'One object of the invention is to provide a simpleand thoroughly practical cam "lapping machine. Another object of the invention is to provide a multiple spindle cam lapping machine, whereby :a plurality-of cams may be simultaneously lapped. Another object of the invention is to provide a cam lapping machine, in which a flexible abrasive element, such as abrasive clothor paper, is rocked toward and from the work axis in a controlled movement-to lap the periphery of the cam to the desired finish.

A further object cfthe invention-is to provide an automatically:operatedcam lapping machine, in which the Elapping operation may be continued for a. predetermined time interval. A further object of the invention is to provide an automatic cam lapping machine which is arranged so'that after the lapping operation has proceeded for a predetermined time interval, the lappingelement will be automaticallyremoved from-thework, the work rotation will be stopped, and'the reciprocation or the work spindle also stopped and the work piece automatically ejected from the machine. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations ofelements,

andarrangements of parts, as will be exemplified in the structure to be'hereinafter described, and the scope'o'f the application of which will be indicated in thelollowing claims.

In the accompanying drawings, in which is shown one of .various possible embodiments of the mechanical features of this invention,

Fig. 71 is-a front elevation of the improved multiple spindle cam lapping machine;

Fig. 2 is a combined hydraulic piping and electrical Wiring diagram;

Fig. 3 is a 'front elevation, on an enlarge of one of the cam'lapping heads;

Fig. 4 is a side elevation, on an-enlarged scale, of one of the cam lapping heads;

Fig. .5 is a vertical sectional View, on an enlarged scale, taken approximately on the line 5 '5 of Fig. 3, through one of the cam lapping heads;

Fig. '6 is a fragmentary rear elevation, on an enlarged scale, of one o'i the cam lapping heads, haying parts broken away-and shown in section;

Fig. '7 is a horizontal sectional view, on an enlarged scale,itaken approximately on the line 'i- 'I of Fig. 5;

Fig.8 is afragmentary frontelevation of the scale,

abrasive lapping element supporting, guiding and feeding mechanism;

Fig. 9 is a fragmentary'side elevation of the mechanism as shown in Fig. '8';

Fig. .10 is a fragmentary detail view of the limit switch-actuating mechanism;

Fig. 11 is a fragmentary sectional view, on an enlarged scale,.showing:the limit switch actuating mechanism;

Fig. '12 is a perspective View, on an enlarged scaie, of the work piece;

Fig. 13 is a fragmentary detail view, on an enlarged scale, of the Work piece, work arbor and spindle, partly in section; and

Fig. 14 isa fragmentary plan view of the guiding mechanism for the work ejector.

The improved cam lappingmachine, as shown in Fig. :1, is a multiple head lapping machine, whereby four work headsmay be simultaneously operated simultaneously to lap a plurality of cams. The heads 2| are identical in construction, consequently only one of the heads has been shown anddescri'bed in detail. The lapping head 2|, thatis, the .left-hand head (*Fig. 1) has been shown indetailin the drawings. The remaining lapping 'headsZl'a, iZIb and H0 have been illustrated only in Fig. .1 and in the diagrammatic showing in -Fig. :2. Corresponding parts of the heads 'Zla, ill) and 210 have been designated where shown by the corresponding reference numeral applied to the lapping head 2! sufiixed with the letters a, b and c.

The lapping head 2! is provided with a rotatable spindle '22 (Fig. 5) whichisrotatablyjournalled in spaced anti-friction bearings "21% and -24. A multi-V-groove pulley 25 is connected to rotate the spindle 22. A motor driving mechanism is provided therefor comprising an electric motor 2% mounted on the upper-surface of the head 2|. A -motor shaft 21 is provided with a multi-V- groove pulley 28 which is connected by a multiple V-belt 29 with the pulley 25 to transmit a rotary motion to the spindle 22. The spindle 22 is a hollow spindle provided with a clearance aperture 30 within which is supported a work supporting spindle 3|. The work spindle 3! is journalled in sleeve bearingsfii and 33 and arranged so that it may be rotated with thehollow spindle 22 and at the same time reciprocated axially during said rotary motion during a lapping operation. The spindle 3| is slidably keyed to a bushingdl which is in turn fixedly mounted relative to'the pulley '28.

A master cam 35 is keyedto a hub 36 which is fixedly mounted to rotate with the-pulley 25 and work spindle 3! (Fig. 5). The master cam 35 serves to control the movement of the lapping element to be hereinafter described. It is desirable to provide means for rotarily adjusting the position of the master cam 35 relative to the spindle 3i and the spindle 22 in order that a work piece 48 supported by the spindle 3| may be positioned in timed relationship with the master cam 35. The hub 33 supporting the master cam 35 is formed as an integral part of a flanged member 37 which is fixedly connected by screws 38 to support the pulley 25. The hollow spindle 22 is provided with an integral flange 39 which has a central aperture 43 to support a hub 4| formed integral with the flange 3? and the hub 35. A plurality of screws 42 serve to hold the flange 3'! in adjusted position relative to the flange 39, only one of these screws being illustrated in Fig. 5. The screw 42 passes through an elongated arcuate slot 43 formed in the flange 31 and is screw threaded into the flange 39 so that the parts may be rotarily adjusted to time the cam 35 relative to the located work piece 48 in setting up the machine.

In order to facilitate rotarily adjusting the master cam 35, a gear segment 44 is cut upon a portion of the periphery of the flange 39. When it is desired to time the cam 35, a pinion having a manually operable handle may be inserted in an aperture 45 into mesh with the gear segment 44. The screws 42' may then be loosened and the pinion meshing with the gear segment 44 rotated to rotarily adjust the flange 3'! relative to the flange 39 to facilitate accurate timing of the master cam 35. After the desired adjustment has been made, the clamping screws 42 may again be clamped to lock the flange 31 to the flange 39, after which no further adjustment is required unless it is desired to change the master cam and to set up the machine for a different lapping operation.

A work supporting adapter 45 is screw threaded onto the front end of the spindle 3| (Figs. 5 and 13). The adapter 46 is provided with a cylindrically shaped work supporting arbor 41 which serves as a support for a work piece 48 having a cam face 49 to be lapped. The adapter 43 is provided with a work locating and driving key 50 which engages a slot cut in the end of the work piece 48 and serves to locate successive work pieces so that the cam 49 is accurately located in timed relationship with the master cam 35.

The arbor 41 serves as a rotatable support for the work piece 48 while the cam 49 is lapped to the desired and predetermined extent. It is desirable to provide a support for the outer end of the work piece to steady it against the thrust of a lapping element to be hereinafter described. A rotatable spring-pressed footstock center 54 is carried by a pivotally mounted footstock 55. The footstock center 44 is arranged to engage a central aperture on the outer end of the work piece 49. In order to facilitate loading and unloading of the machine, the footstock 55 is supported on a vertically extending rock shaft 56 so that it may be swung in a clockwise direction (Fig, 7) to an inoperative position during unloading and loading of work pieces.

The shaft 56 is arranged to be rocked automatically in timed relation with the other mechanisms of the machine such as, for example, by means of a hydraulically operated mechanism comprising a hydraulic cylinder 51 which contains a slidably mounted piston 58. The piston rod 59 carries a head 30 at its left-hand end ward the left (Fig. 7)

(Fig. 7). The head 60 is provided with an elongated slot 6|. A pivotally mounted plate 62 is supported on a rock shaft 63 on the lapping head 2|. The plate 52 is provided with a stud 64 which rotatably supports a roller 65 which in turn rides in the elongated slot 6| in the head 63. The lower end of the rock shaft 55 is provided with an arm 65 having an elongated slot 61. The plate 62 carries a stud 53 which rides within the elongated slot 61. These parts have been illustrated in Fig. 7 in an operative position, in which a work piece 48 has just been lapped to the predetermined extent, and the parts are just about to move into an unloading position.

Fluid under pressure has just been admitted to a cylinder chamber 69 to cause the piston 55 and piston rod 59 to move toward the left (Fig. '7). The movement of the piston rod 59 together with the head 60 and elongated slot 6| toward the left serves to rock the plate 62 in a counterclockwise direction (Fig. '7) about the axis of the rock shaft or stud 63. This movement of the plate 62 causes the stud 68 to ride toward the left within the elongated slot 61 which serves to rock the arm 66, the rock shaft 55, and the footstock 55 together with the work supporting stud or center 54 in a clockwise direction to an inoperative position with the work center 54 out of engagement with the work piece 48. During this movement of the parts, fluid within a cylinder chamber 70 is exhausted in a manner to be hereinafter described into a reservoir H contained within the base of the machine.

A fluid pressure system is provided for conveying fluid under pressure to the cylinders 51, 51a, 51b and 570 and also to other parts of the machine, as will be hereinafter described. The fluid reservoir 'H is supported within the base 20 of the machine. A motor driven fluid pump 12 draws fluid from the reservoir ll through a pipe 73, and forces fluid under pressure through a pipe 14 to'control valves 15, 15a, 15b and 150 on heads 2|, 2| a, 2Ib and H0, respectively, which serve to control the admission of fluid to the cylinders 51, 51a, 57b and 510. A variable pressure relief valve 76 is provided in the pipe line 14 by means of which excess fluid under pressure in the system may be returned through a pipe I! into the reservoir H.

The control valve 15 is a piston type control valve comprising a valve stem 18 having formed integrally therewith valve pistons '59, 80, BI and 82' (Fig. '7). The control valve is hollow, being provided with an axially extending bore 33. In

' the position of the parts as shown in Fig. 7, fluid under pressure from the pipe 14 enters a valve chamber located between the valve pistons and BI and passes through a passage 84 into the cylinder chamber 69 to move the piston 57 to- As previously stated, the parts as shown in Fig. '7 are just as a work piece has been lapped to the predetermined extent and the control valve 15 has been shifted into its right-hand end position by means of a compression spring 85. During the movement of the piston 58 toward the left (Fig. 7), fluid within the cylinder chamber 10 passes out through a passage 86 into a valve chamber located between the valve pistons 79 and 8D and passes through the central aperture or bore 83 within the valve 15 and out through a pipe 81 which exhausts into the reservoir 1| Fluid under pressure exhausting from the cylinders 57a, 51b and 510 passes through pipes 81a, 81b and 810 into the reservoir H. The compression spring 85 surrounds the valve stem 1:8 and is interposed between abracket Z88 fixed on .theslappinghead -2| and a collar 89 which is fixedly mounted on the valve stem 18. The spring *85 normally serves toihold the valve .15 in its right-handiend position,as shown in Fig. '7.

.A manually operable control lever 99 i pivotally mounted on-a stud 9| fixedly mounted on the head EI (Fig. 4). Adownwardly extendin portionof the lever 9!) is connected by a stud '92 with one end of a link A 3. The other end of thelink 9 3 is connected by a stud with a rock arm 95 which-is mounted on the outer end of a rock shaft 96. The rock shaft 96 is journalled in a bearing 91 formed integral with the lapping head frame 2|. A rock arm 98 is fixedly mountedon the inner end of the rockshaft 93. The arm 9-8 supports a stud 99 which rides a groove I99 formed in a spool-shaped member Ifii which is fixedly mounted on the outer end of the valve stem I8. When it is desired to start a lapping cycle, the lever Ellis shifted in a clock- Wise direction (Fig. i) to move the link 93 toward the left (Fig. 4) so as to rock-the arm 95, the rock shaft 93, and the rock arm 98 in a counterclockwise'direction and, through-the stud 99 and spoolshaped member IIH, serves to move the valve stem I8 toward the left (Fig. 7). This movement of the valve stem I8 shifts the valve i5 into its reverse position so that fluid under pressure from the pipe I4 entering the valve chamber located between the valve pistons 8% and 8! passes through the passage 86 into the cylinder chamber ID 'to move the piston '58 toward the right (Fig. '7)

'It is desirable to hold the valve 75 in its lefthand end position (Fig. 7) during a lapping operation. A pivotally'mounted latchltf supported by a stud IE3 is actuated by means of a solenoid I34. When the valve stem i3 is moved into a left-hand end position and the solenoid I'M is energized, the latch'IGZ latches against the collar I03 which is fixedly supported on the valve stem I8. The latch I62 maintains the valve in its lefthand end position while the solenoid Ifli remains energized.

Due to theshape of the workpiece iii, namely, a work piece having oppositely extending arms normal to its axis adjacent to one end thereof, an ejector 'mechanism is provided comprising .a cup-shaped ejector I'IU which is provided with diametrically opposed outwardly extending studs III and H2. A yoke-shaped arm I13 is fixedly mounted on the upper end of a rock shaft H4. The opposed arms of the yoke H3 are eachprovided with elongated slots H5 (Fig. '7) only one of which has been clearly shown in the drawings. The oppositely extending studs III and II2 carried by the ejector IIS arearrangedto slide'in the elongated slots H5. It will be readily apparent from the foregoing disclosure that'if the rock shaft H4 is rocked in a counterclockwise direction (Fig. '7), the arm IE3 will rockalso in a clockwise direction and due to the elongated slots H5, the ejector together with the pins 1 H and H2 may be moved in a straight line path automatically to withdraw the work iece 68 from the supporting arbor 41.

The ejector H is preferably moved in a-substantially straight line path during the ejecting movement. A substantially U-shaped bracket IIB is fixedly mounted on the ejector member IIil (Figs. and 14) A guide block i i-I is fixedly mounted on the lapping head 2I and is provided with parallel guiding surfaces H8 and H9 (Fig. 14) which serve to guide the bracket 1 I5 and the ejector III in a straight line path as .it .isrmoved in .eith'er :direction. It is desirable that the ejector I'll] be moved automatically to and from an operating 'position in'timed relation with the other parts of the machine. This is preferably accomplished by means of a pair of toggle levers I20 and I2I which are connected at their adjacent ends by a stud I22 (Fig. 7). The toggle lever I2I is connected by a stud I23 with the plate 62. The toggle lever I29 is connected by a stud I21 to arockarm I25rmounted "onithe lower end of the rock shaft H4. .At the endtof a lapping operation, when the plate '62 is rocked in a counterclockwise direction by movement of the piston 58 toward theleft, a corresponding movement will be imparted through the stud I23. toggle levers 5.2I and 12%, to rock the arm I25, the rock shaft H4, yokemember H3, in a counterclockwisedirection to move the ejector member I I0 rapidly toward the left so as to withdraw a finish lapped work piece 48 from position on the arbor 41. During the ejecting movement, the toggle levers I29 and I 2| move together until a projecting boss I26 on the lever I20 engages a stop screw I21 on the head 2! after which continued movement of the plate '52 serves to break the toggle levers I20 and I2! from their straight line path of movement during the remainder of the swinging movement of the plate 62. A flat type spring I28 carried by the plate "'62 normally tends to urge the toggle levers IQQ and IZI into a straight line position.

Similarly, at "the start of a lapping operation when the control lever is shifted and the piston 58 moves toward the right (Fig. 7), the movement of the plate 52 in a clockwise direction about its supporting pivot stud 53 serves through the stud I23, toggle levers I2! and I20, and stud I24, to rock the arm I25, the shaft H4, and yoke lit in a clockwise direction, which movement serves'through the studs III and H2 to move the ejector member H9 into an operative position, after which the work piece may be inserted on the arbor before the housing 55 is swung into an operative position with the yieldably'mounted spindle 54 in supporting engagement with the outer portion of the work piece 48.

Work reciprocation A reciprocating mechanism is provided for imparting a rapid reciprocating movement to the work piece 53 during the lapping operation. The rear end of the work spindle 3i supports a sleeve [33 which in turn supports an anti-friction bearingi tbt. A hydraulicreciprocating mechanism is provided comprising a self-contained fluid motor I35 having a cylinder 13?: having a slidably mounted piston 53? therein. The piston I31 is connected to one end of a piston rod 138, the other end of which is supported by the anti-friction bearings Hi l. A control valve is formed as an integral part of the motor I35. The motor I35 has not been illustrated in detail, since this motor is identical with that shown in the prior U. S. patent to Nallace Wood, No. 2,212,871, dated August 27, 1940, to which reference maybe had for details of disclosure not contained herein. The motor I315 contains a slidably mounted piston type pilot valve I353. The pilot valve I39 is hollow, being formed with a central axially extending cylindricalaperture which supports a slidably mounted shuttle type reversing valve MI]. The pilot valve 53!] is provided with a valve stem it which projects from the motor casing and .justable reversing dogs I42 and I43.

is provided at its outer end with a pair of ad- A bracket I44 is fixedly mounted on the motor I35. A pivotally mounted reversing lever I45 is connected by means of a stud I46 with the bracket I44. The reversing lever I45 projects downwardly and is provided at its lower end with a spherical shaped end portion I41 which is arranged in the path of the pilot valve dogs I42 and I43. The reversing lever I45 is connected by means of a :stud I48 with the piston rod I38.

The endwise movement of the piston rod I38 serves to rock the reversing lever I45. When the spherical end I41 of the lever I45 engages either the dog I42 or the dog I43, depending on the direction of movement of the piston I31, continued movement shifts the valve stem I4I to change the position of the pilot valve I39 which operates through the reversing valve I40 to reverse the direction of flow of fluid to the cylinder I36. The operation of the fluid motor I35 is fully disclosed and described in the prior patent to Wood, No. 2,212,871, to which reference may be had for details of operation not contained herein.

The starting and stopping of the fluid motor I35 for reciprocating the work spindle 3| is preferably controlled automatically in timed relation with the other mechanisms of the machine. In the preferred form, a normally closed piston type valve I50 is mounted on the end of the cylinder 51 (Fig. 2). The movable valve member I is normally held in a closed position by means of a compression spring I52. A valve actuating rod I 53 is operatively connected to the piston rod 59 so that when fluid under pressure is admitted to move the piston 58, the valve member I5I will be opened or closed so as to admit fluid to the motor I35 or to cut off fluid under pressure therefrom. Fluid under pressure from the pipe 14 passes through a pipe I54 into a valve chamber I55. In the position shown in Fig. 2, fluid under pressure entering the chamber I 55 passes outwardly through a pipe I 56 to the fluid motor I35. Fluid exhausting from the motor I35 is exhausted directly through a pipe I51 into the reservoir 1I,.

As the piston 58 moves toward the left, the piston rod 59 being connected to the valve stem I53 causes the valve member I 5I to move toward the left aided by the compression of the spring I52 to close the valve, thus preventing passage of fluid from the valve chamber I55 into the pipe I56, thus cutting off fluid under pressure from the work reciprocating motor I35 automatically after the lapping operation has been completed to stop reciprocation of the spindle 3! and work piece 48.

In order to lap the cam 49 to the desired finish, it is essential to provide a lapping element which is movable relatively toward and from the work axis in order that the desired contour may be maintained on the cam 49 during the lapping operation. In the preferred form, a lapping element I60 is mounted on one end of a rock shaft I6I. The rock shaft I 6| is rotatably journalled in bearings I62 and I63 which are formed integral with or fixedly mounted on the lapping head 2I. A rock arm I64 is fixedly mounted on the rear end of the rock shaft I6I. A stud I65 mounted at the upper end of the rock arm I64 serves as a support for a rotatable master cam follower roller I 66. The master cam follower roller I66 is normally maintained in operative engagement with the periphery of the master cam 35 by means of a tension spring I61. The

spring I61 is fastened at one end to a hook I68 fixedly mounted on or adjacent to the upper end of the rock arm I64 and the other end of the spring is fixedly mounted on a stud (not shown) which is fixed relative to the head 2|. It will be readily apparent from the foregoing disclosure that when the work spindle 3I is rotated during a lapping operation, the master cam 35 rotated thereby will impart a controlled oscillating movement to the lapping head I60 so as to maintain the lapping element in uniform operative lapping engagement with the cam 49 during a lapping operation.

Lapping element The lapping element I60 (Figs. 4, 8 and 9) comprises an arm I10 which is fixedly mounted on the rock shaft I6I. The arm I10 supports a pair of spaced side plates HI and I 12 (Fig. 4) which in turn support a lapping head I13. The lapping head I13 is provided with a yieldably mounted nose piece I 14. The head I13 and the nose piece I14 are covered by a piece of flexible yieldable friction material I15 which serves as a support for a strip of abrasive paper or cloth I16. The spring-pressed nose piece I14 is preferably adjusted so that when the master cam roller I66 is riding in engagement with the master cam 35, the nose piece I14 will be under compression to maintain the strip of abrasive paper I16 in uniform lapping engagement with the periphery of the cam being lapped.

In the preferred form a continuous roll of abrasive paper I11 is mounted on a spindle I18 and is supported by side flanges I19 and I (Fig. 4). The strip of abrasive paper I16 passes from the roll I11 over an idler roller I8I and passes downwardly between an idler roller I82 and around the lapping head I13 and nose piece I 14 (Figs. 3, 4, 8 and 9). The abrasive paper I16 then wraps around an idler roller I83 and passes to a paper feeding mechanism.

An abrasive paper indexing or feeding mechanism is provided automatically to advance the abrasive paper I16 a predetermined distance after each lapping operation has been completed to present a fresh portion of abrasive paper I16 around the nose piece I14 for the next lapping operation. By utilizing a fresh portion of abrasive paper for each operation, a uniform lapping or abrading operation may be accomplished in a predetermined time. The feeding mechanism may comprise a pair of corrugated or rough surfaced feed rollers I85 and I86. The roller I85 is rotatably supported on the rock shaft I 6|. The roller I86 is rotatably supported on a stud I81 which is carried by a pivotally mounted frame I88. The frame I88 is pivotally supported on a stud I89 which is in turn supported by the rock arm I10. A compression spring I90 interposed between the upper end of the frame I88 and a projection lug I9I of the rock arm I10 serves to exert a pressure yieldingly to urge the roller I86 toward the roller I85.

The abrasive paper I16, after leaving the nose portion of the head I13, wraps around the idler roller I83 (Fig. 8) and around the left-hand side face of the rock arm I18 and around the feed roller I 85, passes between the feed rollers I85 and I86, and then passes upwardly over an idler roller I92 and is coiled up in a coil I93 located between a plate I94 and the plate I 19. The slack on the return side of the worn abrasive paper is taken up by manual rotation of the disk I94.

A pair of involute gears I95 and I96 are rotatably mounted respectively on the shaft GI and stud I81. The gear I95 is fixedly mounted to rotate with the roller I85 and the gear I96 is fixedly mounted to rotate with the roller I86 so that both of the feed rollers I85 and I86 may be synchronously and positively rotated to produce the desired indexing movement.

A ratchet wheel I91 is mounted on the stud I81 and is fixedly mounted to rotate the gear I96 and the feed roller I86. An index or feed pawl I98 is pivotally supported on a stud I99 and is arranged to remain in operative contact with the teeth of the ratchet wheel I91 by the influence of gravity. The stud I 99 is mounted on one end of a rock arm 269 which is pivotally supported by a stud ZBI on the lapping head 2 I. An arm 202 formed integral with the arm 296 extends in the opposite direction therefrom. A roller 283 is rotatably supported at the outer end of the arm 222 and is arranged in the path of a cam :3. The cam 262 is formed on the outer portion of a quadrant shaped arm 255 which is fixedly mounted to swing with the rock shaft 56 and the housing 55.

When the footstock is rocked to an inoperative position to move the center 54 out of en gagement with the work to facilitate removal of the finish lapped Work piece, the cam 264 swings in a clockwise direction (Fig. 7), which movement swings the cam 254 into engagement with the roller 283 (Fig. 3) after which continued movement serves to rock the lever 29"-= 299 in a clockwise direction (Fig. 3) to cause a downward movement of the feed pawl I99, which movement causes a clockwise indexing movement of the ratchet wheel I91 (Figs. 3 and 8), gear I96 and feed wheel I86 and at the same time, through the gear I96, rotates the gear I95 and the feed roller I85 ina counterclockwise direction to advance the abrasive paper I16, that is, to pull a predetermined amount of the worn abrasive around the nose piece I15, thus presenting a fresh abrading surface for the next lapping operation. The worn abrasive paper feeds downwardly in the direction of an arrow located under the reference numeral I16, consequently the thrust on the abrasive paper I16 is downwardly. The work piece rotates in a counterclockwise direction (Fig. 8) so that the thrust of the rotating work piece 48 is against the positively geared feeding rolls I85 and I86, thus preventing any direct pull or thrust on the new abrasive paper from the roll I11 during the lapping operation.

The pawl I98 is adjustably supported in an arm I98e to facilitate adjustment thereof. The arm I982 is provided with a slot having a groove in its side face to support the pawl I98. A pair of binder or clamping screws I98 and I9Bg are provided to clamp the pawl I96 in adjusted position. If the eifective length of the pawl I98 is decreased or shortened, the arms 296-292 will be maintained in a slightly advanced position in a clockwise direction, under the influence of gravity so that the roller 293 will not be engaged by the cam 264 as quickly during the swinging movement of the cam 284. By adjusting the position of the pawl I98 relative to its supporting arm I98e, the parts may be adjusted so that after each lapping operation one or more teeth of the ratchet wheel I91 may be picked up after each lapping operation has been completed to advance or index the abrasive paper I16 by the desired and predetermined amount.

A mechanism may be provided automatically to separate the lapping element from the work piece and the master. cam follower roller I66 from the master cam 35. after a lapping operation has been completed in order to facilitate removal of the lapped work piece. This mechanism is preferably a hydraulically operated mechanism comprising a fluid pressure cylinder 2H! which is pivotally supported by means of a stud H I on the lapping head 2 l A piston H2 is slidably mounted within the cylinder 2m. and is connected to one end of a piston rod 2I3. The other end of the piston rod 2I3 is connected. by means of a stud 2 it with the rock arm I64 which supports the follower roller I66. A fluid pipe 2I5' is connected between the control valve 15 and the cylinder 2? so that when the valve 15 is in the position as shown in Figs. 2 and '1, fluid under pressure passing through the pipe 14 into a valve chamber located between the valve pistons 96 and BI will pass not only to the cylinder 51 but will also pass through the pipe 2I5 into a cylinder chamber 2I1 to cause the piston 2I2 to move upwardly toward the left to rock the rock arm I62 in a counterclockwise direction so as to separate the master cam follower roller I66 from the master cam 85. The rocking movement of the arm I64 will be transmitted through the rock shaft I6I simultaneously to rock the lapping element away from operative engagement with the work piece. A cylinder chamber located above the piston 252 is connected by a pipe 2I6 with the exhaust pipe 81, whereby any fluid which leaks by the piston 2I2 is free at all times to exhaust into the reservoir 1|.

An electrical control mechanism is provided for each of the lapping heads automatically to control the duration and extent of the lapping operation. The electrical control apparatus consists of push button switches 228, 222d, 22% and 2280 for rendering the lapping head circuit operative. Electrical time delay relays 22 I, 221a, 22Ib and 2216 are provided which may be of any of the standard electrical relays commonly known in the machine tool control art such as, for example, that known as the Microflex manufactured by the Eagle Signal Corporation, of Moline, .Illinois. Magnetic starter switches 222, 222a, 2221) and 2220 are provided rfor controlling the stopping and starting of the electric motors 26, 26a, 26b and 260, respectively. Motor brake switches 223, 223a, 2231: and 223c are provided for rapidly stopping the rotation of the motors 26, 26a, 26b and 260, respectively, at the end of a lapping cycle. Normally open limit switches 224, 222a, 2242) and 2250 are arranged so that they may be automatically closed at the start of the lapping operation. The closing of the limit switches 224, 224a, 2221) and 2220 serves to set the time relays 22!, 2am, 22Ib and 22Ic, respectively, in motion and simultaneously, through the magnetic starter switches 222, 222a, 222band 2220, to start the rotation of the electric motors 26, 25a, 26b and 260 and at the same time to energize the solenoids I2 3, Iii la, I841) and I040 to latch the control valves 15, 15a, 15b and 150, respectively, in an operative position for a lapping operation. After the lapping operation proceeds for a predetermined time intervaLas called for by the setting of the time relay 22I, the relay 221 operates to open the circuit so as to deenergize the solenoid I25, thus releasing the latch I 92 whereupon the released compression of the spring shifts the control valve 15 into the position shown in Figs. 2 and '1. V

The limit switch 224 is preferably actuated in timed relation with the movement of the piston 58 so that when the control lever 98 is shifted to start a lapping cycle, the piston 58 moves toward the right (Fig. 7) to start a lapping operation. The piston rod 51 is provided with a collar 221 which supports a stud 228. A rock arm 229 serves as a support for a stud 230. The rock arm 229 is provided with a yoked portion adjacent to its other end which is connected by a pivot stud 23I with a rock shaft 232. The rock shaft 232 is rotatably journalled in bearings (not shown) within the lapping head 2 I It will thus be seen that the rock arm 229 may be rocked in two directions, namely, about the axis of the shaft 232 as a pivot and also in a plane at right angles thereto about the stud 23I as a pivot. A rock arm 233 (Fig. 7) is fixedly mounted on the rock shaft 232. A pair of opposed balanced compression springs 234 and 235 normally tend to hold the rock arm 233 together with the rock shaft 232 and the rock arm 229 in the position shown in Figs. 7, 10 and 11. The rock arm 229 is provided with a projecting end portion 236 which is normally arranged in the path of an actuating plunger 231 of the limit switch 224.

From the foregoing disclosure it will be readily apparent that if the rock arm 229 is rocked in a counterclockwise direction (Fig. 14) about the axis of the rock shaft 232 as a pivot, the end portion 236 of the rock arm 229 will engage the plunger 231 to close the limit switch 224. It will also be apparent that if the rock arm 229 is moved about the axis of the stud 23I as a pivot, the end portion 236 will be moved laterally out of the path of the switch actuating plunger 231. The parts shown in Figs. '7 and 10 are shown as a work piece has been finish lapped and the lapping cycle is about to be terminated, fluid under pressure having just been admitted through the passage 84 into the cylinder chamber 69 (Fig. 7) to move the piston 58 and piston rod 59 toward the left (Figs. 7 and 10). Movement of the piston rod 59 toward the left moves the collar 221 also toward the left (Fig. 10) and continued movement thereof due to the cam faces of the studs 228 and 238, will swing the rock arm 229 in a counterclockwise direction about the axis of its supporting stud 23I as a pivot so that the end portion 236 thereof will be moved upwardly (Fig. 10) out of the path of the limit switch plunger 231. The collar 221 moves toward the left to the full line position 2210. (Fig. 11) where it remains during the unloading and loading of a work piece.

After the machine has been loaded and it is desired to start a new lapping cycle, the manually operable lever 96 is shifted to move the control valve 15 into a starting position so as to admit fluid under pressure into the cylinder chamber 18 to move the piston 58 toward the right (Fig. 7) which movement shifts the piston rod 59 toward the right, moving the collar 221 from position 221a into the broken line position 221 (Fig. 14). During this mr-vement of the collar 221 toward the right, a cam face on the stud 228 (on the collar 221) engages a cam face on the stud 238 (on the rock arm 229) (Fig. 14) which serves to rock the rock arm 229 in a counterclockwise direction (Figs. '7 and 14) about the axis of the rock shaft 232, which movement shifts the end portion 236 into engagement with the actuating plunger 231 of the limit switch 224 to close the limit switch 224 in a manner above described, serving to set the time relay 22I in motion, through the electric magnet starter switch 222,

to start the work drive motor 26 and at the same time energize the solenoid I04 to move the latch I62 upwardly to latch the valve 15 in an operative position. It will thus be seen that when the collar 221 moves in a direction toward the left after a lapping operation has been completed, the arm 229 is moved out of operative contact out of the path of the plunger 231 of the limit switch 224 and on the return stroke of the collar 221 at the start of the next lapping operation, the lever 229 is swung so that its operative end portion 236 engages and actuates the limit switch plunger 231 to close the normally open limit switch 224 to initiate the next lapping cycle. All the lapping heads 2Ia, 2Ib and 2Ic operate in the same manner.

The operation of the improved cam lapping machine will be readily apparent from the foregoing disclosure. Assuming all of the parts and mechanisms to have been previously adjusted, the operator closes the push button switches 220, 228a, 2213b and 2200 which render the machine circuits in condition for operation. A work piece 48 is then manually placed in position on the work supporting arbor 41 with the driving key 58 engaging the notch formed in the right-hand end of the work piece (Fig. 13). The control lever 98 is then manually shifted in a clockwise direction (Fig. 4), which movement operates in a manner above described to shift the control valve stem 18 toward the left (Fig. '7), which positions the valve 15 so that fluid under pressure from the pipe 14 is admitted to the cylinder chamber 10 to move the piston 58 toward the right into the position illustrated in Fig. '7.

During this movement of the piston 58, the footstock 55 is shifted in a counterclockwise direction to the position illustrated in Fig. '7 with the work supporting, spring pressed plunger 54 (Fig. 5) in operative supporting engagement with the work piece 48. Also during the movement of the piston 58 toward the right, the limit switch 224 will be closed in a manner above described and held closed for a brief period due to the shape of the cam faces on the studs 228 and 230. The closing of the limit switch 224 serves to set the time relay 22I in motion, also through the magnetic starter switch 222 to start the motor 26 to rotate the work piece 48, and at the same time to energize the solenoid I04 which lifts the latch I62 so as to hold the valve 15 in an operating position during the lapping operation. In this position of the valve 15, fluid within the cylinder chamber 2I1 (Fig. 6) exhausts through the pipe 2I5 into a valve chamber located between the valve pistons BI and 82 and out through the pipe 81 into the reservoir H. The released tension of the spring I61 serves to facilitate this movement and rapidly to swing the master cam follower roller I66 into operative engagement with the periphery of the master cam 35. This movement of the master cam follower roller I66 serves to rock the rock shaft I6I so as to move the lapping element I68 into an operative position with the abrasive paper I14 in operative engagement with the periphery of the cam 49 to be lapped.

During movement of the piston 58 into its right-hand end position at the start of a lapping operation, the valve I5I is opened so that fluid under pressure within the pipe 14 passes through the pipe I54, the valve chamber I55, and the pipe I 56 to the fluid motor I35 to start reciprocation of the piston I31 which is transmitted to the piston rod I38 to oscillate or reciprocate the 2,290,755 worksupporting spindle. 3! so that the. cam.49.

being lapped is reciprocated in an axial directionat a comparatively rapid rate during its rotation so that a highlylfinished surface is produced on thework piece by the lapping operation.

The lapping operation continues for a-prede-- termined time interval as governed by thesetting of the electric time delay relay 225. After the predetermined time. interval has elapsed, the time relay 22! breaks a circuit to deenergize the solenoid H34, which movement serves to release the latch I82; thus releasing the compression of the spring 85 which moves the valve rapidly toward the right into the position shown in Figs. 2 and 7. The initial movement-of the valve 75 toward the right is retarded by means of a stop screw 2 18 -(Fig.- 9) which is engaged by a lug 2M formed on the inner surface of the link 93. The stop screw 2% and lug 2t! hold the valve 15 ina central position so that fluid under pressure in the pipe la'ipassing into the valve chamber located between the valve pistons fill-and 85 may pass only through pipe 2 l 5 into the cylinder chamber (Fig. 6), which movement serves to separate the master cam follower roller 566 from the master cam and at the same time serves to rock the arm H6 in a clockwise direction (Fig. 8) to move the abrasive lapping paper H6 out of operative engagement with the cam 49 being lapped.

During this swinging movement of the arm iii), the screw 26-53 is swung also in a clockwise direction (Fig. 8) out of the path of the stop lug 24!, after which the compression of the spring- 85 is againrelea-sed to complete the movement of the valvestein 78 into its right-hand end position. After the valve 75 has reached its right-hand end position (Fig. 7) fluid under pressure is admitted into the cylinder chamber 69 to start the piston 58 moving toward the left; serves in amanner above described to remove the footstock 55, andthe work supporting springpressed plunger 5 to an inoperative position and at the same time serves through the toggle levers I20 and I2! rapidly toshift the work ejector member H3 toward the left (Fig. 7) to eject a finish lapped work piece 18 from the work supporting arbor 6'7, thus completing the lapping operation.

After, the predeterminedv time interval, the,

time relay 221, not only breaks the circuit to deenergize thesolenoid ltd but ,also, through the magnetic starterswitch 222 and the motor break switch 223, instantaneously stops the rotation of.

the work supporting and driving spindle 3!. The machine is nowincondition for loading the next work piece 5-8 to be manually loaded into supporting engagement with the work supporting arbor 41.

It will be readily apparent from the foregoing disclosure that work pieces 48 are manually loaded into supporting position on the work supporting arbor 4! on each of the lapping heads 2!,

21a, Zlb and Mo, after which the control levers 90, 90a, 96b and 980 may be shifted to initiate a lapping cycle. After a lapping operation has been completed, the lapped work pieces are automatically ejected and the head stopped to rfacilitate loading a new work piece into position for the next lapping operation.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embod- This movement.

iments may be made of theabove'invention and as many changes might be made in. theembodiment above set forth, it is to bev understood that all matter hereinbefore set forth or shown in the I accompanying drawings is to be interpreted as illustrative and not in a lirniting sense.

We claim:

1. In a cam lapping machine-having a .base, a rotatable work supporting spindleto support a cam to be lapped, meansto rotatesaid spindle, means to reciprocate said spindle axially within its bearings. a movable lapping element, means including a master cam and a follower inter posed between said spindle and said lapping element to impart an oscillating movement to the lapping element during a lapping operation;

2. In a cam lapping machine having a base, arotatable work supporting spindle to support a cam to'be lapped, means-to rotate said spindle, means to reciprocate said spindle axially within" its bearings, a pivotally mountedlapping e1-' ment, means including a-master-canrand a follower interposed between said spindle and said lapping elementto impart'an oscillating movement to the lapping element during a lapping operation.

3. In a cam lapping machine having 'a base, a rotatable work supportingspindle to support a cam to be lapped, means'including an electric motor to rotate said spindle, means to rotate said spindle, means to reciprocate said spindle axially, a .pivotally mounted lapping element, a rock shaft to support said-element; a master cam on said work spindle, and a master cam follower roller cooperating with said master care to oscillate said rock shaft during rotation of the work spindle to imparta controlled oscillating movement to the lapping element to produce the desired lapping action.

4. In a cam lapping machine having a base, a rotatable work supporting spindle rotatably to support a cam to be lapped, bearings in said base for said spindle, means including an electric motor to rotate said spindle, means including a fluid motor to reciprocate said spindle axially within its bearings, a pivotallymounted lapping element, a rock shaft to support said element, a

master cam follower roller, an arm on said rock shaft to support said roller, and a master cam on said work spindle to impart a controlled oscillating movement vto the follower roller and rock shaft to the lapping element.

5. In a cam lapping machine having a base, a rotatable work supporting spindle rotatablyjto' support a cam to be lappedya footstock which is movable to and from an operative position, means to move said footstock, a lapping element including a continuous strip of flexible abrasive paper, an indexing mechanism including a pawl and ratchet to feed said abrasive paper, and means actuated automatically when the footstock is moved to an inoperative position automatically to advance said paper so as to present a fresh portion of abrasive paper for the next lapping operation.

6. In a cam lapping machine having a base, a rotatable work supporting spindle rotatably to support a cam to be lapped, a movable footstock, means to move said footstock to and from an operative position to facilitate a work loading operation, a lapping element including a continuous strip of flexible abrasive paper, an indexing mechanism including a pawl and ratchet to feed said abrasive paper, and a cam actuated by said footstock automatically to actuate said pawl to advance said abrasive paper automatically after each lapping operation has been completed.

'7. In a cam lapping machine having a base, a rotatable work supporting spindle rotatably to support a cam to be lapped, a pivotally mounted footstock, means to swing said footstock to and from an operative position, a lapping element comprising a continuous strip of flexible abrasive paper, an indexing mechanism including a pawl and ratchet to feed said abrasive paper, a cam actuated by said footstock, and a pivotally mounted lever interposed between said cam and said pawl whereby the pawl is automatically actuated when the footstock is moved to an inoperative position to index said abrasive paper so as to present a fresh portion of abrasive paper for the next lapping operation.

8. In a cam lapping machine having a base, a rotatable work supporting spindle rotatably to support a cam to be lapped, a pivotally mounted footstock, means to move said footstock to and from an operative position, a master cam on said spindle, a lapping element including a continuous strip of flexible abrasive paper, ,a master cam follower roller associated with said master cam and arranged to move said lapping element to impart a controlled movement to said lapping element, an indexing mechanism including a. pawl and ratchet to feed said abrasive paper, and a cam actuated by said footstock automatically to advance said abrasive paper after each lapping operation so as to present a fresh portion of abrasive paper for the next lapping operation.

9. In a cam lapping machine having a base, a

rotatable work supporting spindle to support a v cam to be lapped, a fluid motor to reciprocate said spindle, an electric motor to rotate said spindle, a pivotally mounted foo-tstock to support one end of a work piece, a pivotally mounted work ejector, a fluid pressure operated piston and cylinder, operative connections between said piston and said rootstock and ejector, a valve to control said fluid motor, means actuated by said piston to open said valve to start the fluid motor, and electrically actuated means including a switch actuated in timed relation with said piston to start said electric motor to rotate the work piece.

10. In a cam lapping machine having a base, a rotatable work spindle to support a cam to be lapped, a fluid motor to reciprocate said spindle,

an electric motor to rotate said spindle, a pivotally mounted footstock to support one end of a work piece, a pivotally mounted work ejector, a fluid pressure operated piston and cylinder, operative connections between said piston and said footstock and ejector, a stop and start valve to control said fluid motor, means actuated by said piston to open said valve to start the fluid motor, and electrically operated means including a switch actuated by and in timed relation with movement of said piston in one direction to close a circuit to start rotation of the electric motor and spindle.

11. In a cam lapping machine having a base, a rotatable work spindle to support a cam to be lapped, a fluid motor to reciprocate said spindle, an electric motor to rotate said spindle, a pivotally mounted footstock to support one end of a cam to be lapped, a pivotally mounted work ejector, a fluid pressure operated piston and cylinder, a control valve therefor, means including a solenoid actuated latch to hold said valve in an operative position, operative connections between said piston and said footstock and ejector to actuate the footstock and ejector, a valve to control said fluid motor, means actuated by said piston to open said valve to start said fluid motor, electrically actuated means including a switch actuated in timed relation with said piston to start said electric motor, and an electric time relay which is set in motion by said switch, said relay being arranged to deenergize said solenoid after a predetermined lapping operation.

1 In a cam lapping machine having a base, a rotatable work spindle to support a cam to be lapped, a fluid motor to reciprocate said spindle, an electric motor to rotate said spindle, a pivotally mounted footstock to support one end of a cam to be lapped, a pivotally mounted work ejector, a fluid pressure operated piston and cylinder, a control valve therefor, means including a solenoid actuated latch to hold said valve in an operative position, operative connections between said piston and said footstock and ejector to actuate the footstock and ejector, a valve to control said fluid motor, means actuated by said piston to open said valve to start said fluid motor, electrically actuated means including a switch actuated in timed relation with said piston to start said electric motor, and an electric time relay which is set in motion by said switch, said relay being operatively connected to stop the work drive motor and the work rotation and to deenergize said solenoid to shift said control valve and cause the piston to move to an inoperative position, which movement closes said start and stop valve to stop the fluid motor and the reciprocation of the work spindle, swings said footstock to an inoperative position, and actuates said ejector automatically to eject a lapped work piece.

HERBERT S.. INDGE. JOHN C. BAKER. 

